/**
 * struct ListNode {
 *	int val;
 *	struct ListNode *next;
 *	ListNode(int x) : val(x), next(nullptr) {}
 * };
 */
class Solution {
public:
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param pHead1 ListNode类 
     * @param pHead2 ListNode类 
     * @return ListNode类
     */
    ListNode* Merge(ListNode* pHead1, ListNode* pHead2) {
        if(pHead1 == nullptr||pHead2 == nullptr)
        {
            return pHead1?pHead1:pHead2;
        }
        ListNode* cur1 = pHead1;
        ListNode* cur2 = pHead2;
        ListNode newhead(0);
        ListNode* cur = &newhead;
        while(cur1&&cur2)
        {
            if(cur1->val<cur2->val)
            {
                cur->next = cur1;
                cur1 = cur1->next;
            }
            else {
                cur->next = cur2;
                cur2 = cur2->next;
            }
            cur = cur->next;
        }
        cur->next = cur1?cur1:cur2;//链接后面有序的节点
        return newhead.next;
    }
};